ALL ABOUT BIRDS
Birds are warm-blooded vertebrate animals that have wings, feathers, a beak, no teeth a skeleton in which many bones are fused together or are absent, and an extremely efficient, one-way breathing system. Flying birds have strong, hollow bones and powerful flight muscles. Most birds can fly. Birds have a very strong heart and an efficient way of breathing these are necessary for birds to fly. Birds also use a lot of energy while flying and need to eat a lot of food to power their flight. Not all flying animals are birds, and not all birds can fly. MOVING: Flying, Running, and Swimming: The locomotion of birds is quite varied; most can fly, some can run very well, some swim, and some do combinations of these. Some birds cannot fly. Most birds can fly. Flying bird`s wings are shaped to provide lift, allowing them to fly. These light-weight animals have adapted to their environment by flying, which makes them efficient hunters, lets them escape from hungry predators (like cats), and takes them away from harsh weather (migration). The peregrine falcon is one of the fastest birds, and has been clocked at 90 miles per hour in a dive (and some people say that they can dive at over 200 mph). Feathers: There are different types of feathers and they each have different uses. Feathers are used for: *[http://www.ucmp.berkeley.edu/vertebrates/flight/aves.html Flying ]- flight feathers, grow in the wings and the tail. *'Thermal insulation' - soft down feathers that grow close to the skin keep birds from getting too cold or too hot *'Courtship and mating displays' - these vary tremendously from species to species. Diet: Modern-day birds do not have any teeth (ancient birds did have teeth). Birds have a tongue, but unlike our tongue, a bird's tongue has a bone in it. Birds spend most of their time looking for food. Most birds are insectivores (they eat insects). Some birds, like owls and eagles, are carnivores (meat-eaters). Some birds, like the hummingbird, grouse, and Canada goose, are mostly herbivores (plant-eaters). Other birds, like starlings, are omnivores (plant- and meat-eaters). Some birds (like the toucan) are fructivore (fruit-eaters) Birds mostly use their keen eyesight to find food. They use their beak and their claws to get bugs, worms, small mammals, fish, fruit, grain, or nectar. Birds play a very important part in the natural control of insects and in the dispersal of seeds. Some birds, like the tiny, nectar-eating hummingbird are important pollinators of some flowering plants. Nests and Eggs: Birds bear their young in [http://www.ucmp.berkeley.edu/vertebrates/tetrapods/amniota.html hard-shelled eggs] which hatch after some time. Some birds, like chickens, lay eggs each day, others (like the maleo) may go for years between laying eggs. Birds build nests for breeding in trees, on cliffs, or on the ground. Most birds are taken care of by at least one parent until they are able to fly and get their own food. The incubation period of bird eggs varies from species to species. There's also some variability due to the temperature. Some birds, like old-world cuckoos and some cowbirds, lay their eggs in other bird's nests. The non-related adult bird takes care of the cuckoo's egg unwittingly. Some cuckoos even kill the other eggs in the nest to insure that their egg gets enough food. ' ' Migration: ''' Many bird species migrate to a cooler climate for reproducing and summer feeding, and then return to a warmer climate for the winter. It is unknown exactly how birds are able to navigate accurately, but many people are studying this mystery of how birds know where to fly. '''The Classification of Birds: Birds belong to the biological class Aves and live virtually everywhere on Earth. Birds are amniotes, animals whose eggs are protected from drying out (a group that includes the mammals, birds, dinosaurs, and reptiles). There are about 9,000 different species of birds, divided into 24 orders and 146 Families. Most birds alive today are Neognathae (a group distinguished by common palate structure). Another, much smaller group, is the Palaeognathae (again grouped by palate structure), which includes the ostrich, kiwi, emu, rhea, and others. The Evolution of Birds: Birds probably evolved from meat-eating (theropod) dinosaurs during the Mesozoic Era, roughly 150 million years ago. Early birds, like Archaeopteryx, had teeth in their mouth and claws on their wings. Bird Songs: Birds sing beautiful and diversified songs. Many songbirds are becoming scarcer every year. Songbirds have a vocal organ called the syrinx located in the throat. The muscular syrinx has two halves that each vibrate to produce songs, so the bird can sing two notes at a time. To sing, a bird blows air from the lungs through the syrinx. Do Bird Have Knees? Why Do Their Legs Bend Backwards? Yes, birds have knees (they're often under the feathers and not easily visible), and they bend the same way our knees bend. The part of a bird's legs that bends backwards when it walks is the ankle. Heart Rate and Breathing: In order to fly, birds need a lot of oxygen, which they get by breathing air using lungs. They also need a strong circulatory system, including a powerful heart in order to circulate the oxygen. A bird's heart beats much faster than our heart does. A hummingbird's heart beats about 1,000 times each minute; a human's heart beats about 60-90 times each minute. Birds breathe using a unique system in which air follows a one-way route through the respiratory system. This system is unlike our lungs, in which the air backtracks where it came from. Their system of respiration (breathing) is very efficient - much more efficient than our system. Birds have two relatively small lungs (where gas exchange occurs), but the lungs are augmented by bellows-like air sacs (where no gas exchange occurs). These air sacs keep the lungs perpetually inflated (even when the bird is exhaling). Our lungs alternately fill and empty out. The bird's respiratory system takes up 20% of a birds's volume (our respiratory system takes up only 5% of our volume). In the bird's respiratory system, air first flows through air sacs (located even inside their hollow bones) that direct fresh, oxygenated air into the tube-like lungs (parabronchi, where gas exchange occurs) both when the bird inhales and when it exhales. This system increases birds' respiratory efficiency and gives them enough oxygen for flight. Why Can Birds Perch on Power Lines? Birds can often safely perch on a power line without being electrocuted. For the bird (or other animal) to be electrocuted, a potential difference must exist across two points of the bird's body (its feet in the case of a bird on a power line). When perching on a single power line, there is no potential difference between the bird's feet, so it is safe. If the bird (or other animal) touches two power lines at a time, or one power line and a ground (like a ground wire or the earth itself), the animal would be electrocuted and die. Many large birds (like eagles and vultures) are electrocuted when their wide wings touch a power line and a ground wire at the same time (often while flying in to land on a power line). Bird Facts: Ornithology is the study of birds. A scientist who studies birds is called an ornithologist. The fastest running bird is the ostrich, but it cannot fly. The ostrich is also the fastest'' two-legged runner of all the animals on Earth. The ostrich is the large The ostrich lays the '''largest bird`s eggs'; their eggs are up to 4.5 x 7 inches (11 x 18 cm) across and weigh 3 pounds (1400 g).st bird.